@joncruz @noiob @Siff I get the feeling it's a little bit of everything and the texture of the PEI plate around the Perimeter looking good was somewhat of a red hering. Trying the things recommended on their own didn't really solve the issue (very slow speed <15mm/s 'seemed' to do something).
Lowering the nozzle by additional 0.05mm, going 10°C+ higher in temps for the first layer and wiping the plate with isoprop once again (or using the very edge that got never used) seem to improve things.
@joncruz @noiob @Siff Lowering the nozzle by those 0.05mm now causes the outer perimeter to have a slight "wobble" though… (the filament got squeezed outwards through the textured plate). Meanwhile the center of the infill still got very little to no of the PEI texture. It really behaves as if the nozzle moves upwards towards the center (no matter where on the plate I print), this is super weird. Might try to go further up with the first layer temp so the material has more time to fill the gaps.
@Natanox do you have a bed probe? I suspect your build plate is not exactly flat
@Natanox oh, and it kinda looks like the first layer is getting blown away by part cooling, maybe turning that off in the first layer would help (though it'd only be a stopgap vs better bed adhesion)
@noiob I do have a probe, the bed gets measured for every print. The cooling is disabled for the first two layers.